The electromagnetic spectrum in the range of the terahertz frequency band may provide information concerning the complex chemical composition of materials and the dielectric properties of objects. For this application, quite complex systems are currently used which contain pulsed laser sources, for example. Besides the complexity, a significant weakness of the available terahertz systems is that a measurement solely in the terahertz frequency band is not very meaningful, and often must be supplemented by simultaneous measurements in the visible or infrared frequency band. This is usually carried out by the simultaneous use of multiple detectors or detection systems which require a complex mutual optical alignment, which results in high costs for the overall system.